refactor(sidebar): collapse rail/sections to single-IA, log docs

- Sidebar: kill the drifting railGroups + sections dual definition.
  Single source of truth (workItems / libraryItems / footerItems)
  rendered in both pinned and rail modes; pin/unpin is a width and
  label affordance, not an IA switch. Hairline divider replaces
  section labels. Guides moves to the footer alongside Account.
  Renames: Home -> Dashboard, History -> Sessions, Insights -> Analytics.
- CURRENT-STATE.md: log PR #158 (session impeccable pass + tasklane
  keyboard flow) under "Recently shipped".
- PRODUCT.md: design-context source of truth (users, brand, aesthetic);
  sibling to DESIGN-SYSTEM.md.
- skills-lock.json: lock /impeccable + /documentation-writer skill
  versions so other sessions reproduce the same tooling state.
- Drop stale .impeccable.md.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CURRENT-STATE.md

@@ -12,6 +12,7 @@
 
 ## Recently shipped (post-0.1.0.0)
 
+- **2026-05-01 — PR #158** Session-screen UX impeccable pass + tasklane keyboard flow. Heuristic score 24/40 → 33/40 across five sub-passes (distill, quieter, layout, typeset, polish). Removed duplicate "Suggested checks" chip strip → TaskLane is the single source of truth; added inline `Next steps · N pending` cue on the latest action-bearing AI bubble; consolidated session header to Resolve + Escalate + ⋯ kebab; centered messages column to match composer; dropped all banned decorations (side stripes, gradient surfaces, backdrop blur, accent borderTop) for a single decoration channel per surface; unified 14 text sizes into a 5-step scale. TaskLane keyboard flow: Enter submits + auto-advances, Shift+Enter newline, Esc cancel, focus jumps to Send after the last task. Banner ↔ script-panel are now linked (collapse hides both, any outcome closes both). WhatWeKnow section is collapsible with `sessionStorage` memory + auto-collapse-at-5-facts. Side fix: ParameterizationPreview no longer over-highlights short parameter values (word-boundary check). Two backlog entries logged in `.ai/TODO.md`: ConcludeSessionModal multi-select and `bg-card-hover` Tailwind drift in CommandPalette.
 - **2026-05-01 — PR #156** Suggested-fix "Awaiting verification" outcome. Engineers can now park a fix in `applied_pending` (waiting on client power-cycle, AD replication, license sync, etc.) instead of forcing a synchronous worked/didn't/partial verdict. PendingBanner with worked / didn't / update reason / dismiss; nudge "Still checking" records pending with a reason; page-level Resolve auto-patches pending → success before the resolution flow opens; page-level Escalate intercepts pending. Migration `c0f3a4b7e91d` (`pending_reason` column + status CHECK constraint).
 - **2026-04-30 — PR #155** Escalation Mode wedge. Magic-moment handoff-context screen for senior pickup, live SSE escalation arrivals, post-claim time-to-first-action metric (`GET /analytics/flowpilot/escalations`), atomic role-gated claim with conflict resolution, queue self-exclusion, chat ownership extended to claimed sessions. The wedge for the first paying-customer push.